Hi Nick,
Welcome to post in our forum.
Based on your description, you want to configure phone numbers for users using Cloud PBX and PSTN for SFB online, please refer to the following document:
Set up PSTN Calling for Skype for Business
https://support.office.com/en-us/article/Set-up-PSTN-Calling-for-Skype-for-Business-57893158-1acd-44ac-acaf-19f58264a9e0
Assign a phone number in Skype for Business
https://support.office.com/en-us/article/Assign-a-phone-number-in-Skype-for-Business-91089761-cb87-4119-885b-3713840dd9f7
According to my research, auto attendant and Polycom VVX 600 can’t distinguish the call type, after we create a Unified Messaging (UM) auto attendant, incoming calls to an external telephone number that a human operator would ordinarily answer are answered
by the auto attendant.
The following blog mainly describes auto attendant, please refer to
https://technet.microsoft.com/en-us/library/aa998875(v=exchg.150).aspx
https://technet.microsoft.com/en-us/library/jj673508(v=exchg.150).aspx
Moreover, since you use SFB online, you could also post in SFB online forum, there are more experts will help you with this issue, thanks for your understanding.
http://answers.microsoft.com/en-us/msoffice
Regards,
Alice Wang
Please remember to
mark the replies as answers if they help.
If you have feedback for TechNet Subscriber Support, contact
tnmff@microsoft.com.